The present inventive concept relates to a semiconductor device, and more particularly, to a semiconductor device having a multi access level which can restrict an access range according to an inputted password, and an access control method thereof.
As the semiconductor industry develops, semiconductor devices, for example, various electronic devices using semiconductor chips, are being developed. According to a type of an electronic device, data requiring security such as personal information, financial information, etc., may be stored in a semiconductor chip. Also, a semiconductor chip built in an electronic device can store program codes to control every operation of the electronic device. Therefore, access to a semiconductor chip built in an electronic device has to be restrictively permitted.
A semiconductor chip built in an electronic device may include a JTAG (joint test action group) interface for test or debugging. A test or debugging of a semiconductor chip through the JTAG interface is performed by an authorized user to protect data stored in a semiconductor device. Thus, an approach which can restrict access to a semiconductor chip through the JTAG interface is required.
As semiconductor chips have become smaller, and devices and conductors on the chips have become finer and more complex, a system on chip (SOC) has been introduced. Generally, SOC includes all the hardware and software constituting an integration circuit, such as a processor, a memory, an external interface, an analog and mixed mode block, built-in software and an operating system (OS). The data stored in a memory included in a SOC may be program code for operating an electronic device, application program code, personal information and/or financial information. For instance, an application programmer has to be allowed to access an application program stored in a memory to debug the application program but has to be restricted to access program code for driving an electronic device. Thus, a method which can restrict access to a semiconductor chip depending on a user is needed.